Hitherto, there have been made various studies concerning polymerization of higher α-olefins having 10 or more carbon using mainly Ziegler/Natta catalysts.
For instance, the above studies have been reported in “Polymer J.”, 10, 619, (1978), “Macromol. Chem.”, 190, 2683 (1989), “Makromol. Chem., Rapid Comm.”, 13, 447 (1992), Japanese Patent Application Laid-open No. Hei 7-145205, etc.
However, the higher α-olefin polymers described in these literatures tend to have a low molecular weight as well as a high melting point due to a high regularity thereof, and further tend to exhibit a non-uniformity owing to existence of two melting points thereof, etc.
In addition, in “Macromol. Sci. Pure Appl. Chem.”, A35, 473 (1998), “J. Polym. Sci.”, A, 38, 233 (2000), “Macromol. Mater. Eng.”, 286, 480 (2001) and “Macromol. Matr. Eng.”, 286, 350 (2001), it is described that higher α-olefin polymers are produced in the presence of homogeneous catalysts called metallocene catalysts.
However, the polymers produced in the presence of such homogeneous catalysts also fail to exhibit a sufficiently high molecular weight, and have a high melting point due to a high regularity thereof, and further show a non-uniformity owing to existence of two melting points, similarly to the above-described polymers obtained using the heterogeneous catalysts.
The polymers having a plurality of melting points tend to be non-uniform in crystal size, etc., which may result in occurrence of stickiness.
Further, when such polymers are blended as a modifier with other resins, the resultant blend tends to be non-uniform, thereby failing to modify properties of the resins as desired.
Also, in the applications such as heat accumulating agents, in order to enhance a heat accumulating efficiency, it is required that resins used therein cause abrupt exothermic or endothermic reaction due to abrupt melting or crystallization thereof at a specific temperature. Therefore, it will be difficult to use the above non-uniform resins in such applications.
Accordingly, an object of the present invention is to provide a crystalline higher α-olefin polymer that is excellent in compatibility with thermoplastic resins, especially polyolefins, compatibility with lubricating oils, fuel oils or waxes, mixability with inorganic fillers and fabricability (secondary processability) and has a narrow melting or crystallization temperature range, and a process producing the same.